Cleaning a House is One Thing, Try Cleaning a 100 Million Dollar, 500 Year Old Painting
Take a trip to your local museum, and you'll find that the paintings inside often look as good as new, despite many being hundreds of years old! But how do you clean and preserve an old painting to keep it in that condition? In the world of art conservation, cleaning old paintings is both an art and a little bit of a science, too. Behind every brushstroke lies a story, and it's the job of conservators to reveal these stories while preserving the integrity of the artwork. Here's how they do it:
Step 1: Surface Cleaning
The first step in cleaning an old painting is surface cleaning. Using soft brushes, sponges, or microfiber cloths, conservators gently remove dust, dirt, and other surface contaminants. This initial cleaning helps improve the overall appearance of the painting and prepares it for more intensive cleaning treatments.
Step 2: Varnish Removal
Over time, the varnish applied to protect the painting can become discolored or yellowed, obscuring the original colors and details of the artwork. Conservators carefully remove the old varnish using solvents and other gentle techniques. To see an example of this process's effect on a painting, see before and after pictures Rembrandt's "The Night Watch" and notice how the rich hues and subtle details were brought back to life after the removal of yellowed varnish. In fact, "The Night Watch" was given that name long after it was painted, by people under the mistaken impression that it depicted a night scene, when, in fact, it just desperately needed a cleaning.
Step 3: Cleaning the Paint Layers
Sometimes, the paint layers themselves may require cleaning to remove embedded dirt, grime, or discolored retouching from previous restoration attempts. Conservators use specialized cleaning solutions and techniques tailored to the specific materials and techniques used in the painting. This is the most delicate part of the cleaning process. Several methods may be used:
Swabbing with Solvents: Conservators may use solvents to dissolve and remove stubborn dirt, grime, or varnish from the paint layers. This process involves carefully applying solvents to the surface of the painting using cotton swabs or brushes. The choice of solvent and application method depends on factors such as the type of dirt or varnish present and the sensitivity of the paint layers.
Poultice Applications: For particularly stubborn or ingrained dirt, conservators may use poultices—soft, absorbent materials soaked in a solvent or cleaning solution. The poultice is applied to the surface of the painting and left to absorb the dirt before being carefully removed, taking the dirt with it.
Mechanical Cleaning: In some cases, conservators may use mechanical methods to clean the paint layers. This could involve gently scraping or lightly abrading the surface of the painting with specialized tools to remove dirt or old varnish layers. Mechanical cleaning requires a delicate touch to avoid damaging the paint.
Gel Cleaning: Gel cleaning involves applying a specialized cleaning gel or paste to the surface of the painting. The gel adheres to the dirt or varnish, allowing conservators to carefully lift it away from the paint layers. Gel cleaning is particularly useful for removing aged or stubborn coatings without risking damage to the paint.
Enzyme Cleaning: Enzyme cleaning is a gentle yet effective method for removing biological contaminants, such as mold or mildew, from the paint layers. Conservators apply enzyme solutions to the affected areas, where the enzymes break down and digest the organic matter, making it easier to remove.
Ultrasonic Cleaning: In some advanced conservation laboratories, ultrasonic cleaning technology may be used to clean paint layers. Ultrasonic waves create microscopic bubbles in a cleaning solution, which implode upon contact with the surface of the painting, dislodging dirt and contaminants without causing damage.
Step 4: Consolidation and Stabilization
If the painting has areas of flaking or unstable paint, conservators may need to consolidate and stabilize these areas to prevent further damage. This typically involves applying a conservation-grade adhesive to secure loose paint flakes. In "The Last Supper" by Leonardo da Vinci, careful consolidation and stabilization efforts have preserved the iconic painting for future generations to admire.
Step 5: Retouching and Inpainting
After cleaning and stabilization, conservators may carefully retouch areas of loss or damage to restore the painting's appearance. This process, known as inpainting, involves using conservation-grade paints and pigments to match the original colors. Pablo Picasso's "Guernica" has been seamlessly inpainted to integrate repaired areas with surrounding paint layers.
And there you have it. Cleaning old paintings is a meticulous process that requires skill, patience, and a deep understanding of both art and science (not too much different from cleaning houses, though the right tools and equipment helps!) Through the careful examination, surface cleaning, varnish removal, paint layer cleaning, consolidation, and retouching processes used by conservators, old masterworks are preserved for future generations to enjoy.